1. Field of the Invention
The present invention relates in general to data storage systems such as disk drives. This invention relates in particular to a read/write head for use in magnetic and magneto-optical data storage systems to enable writing of data to a magnetic data storage medium with the assistance of laser heating. More specifically, the head allows magnetic reading of data from the storage medium, and thermally assisted magnetic writing of data on the storage medium, thus significantly improving the thermal stability of the recorded data.
2. Description of Related Art
A conventional magnetic storage system typically includes a magnetic head that has a slider element and a magnetic read/write element, and is coupled to a rotary actuator magnet and a voice coil assembly by a suspension and an actuator arm positioned over a surface of a spinning magnetic disk. In operation, a lift force is generated by the aerodynamic interaction between the magnetic head and the spinning magnetic disk. The lift force is opposed by equal and opposite spring forces applied by the suspension such that a predetermined flying height is maintained over a full radial stroke of the rotary actuator assembly above the surface of the spinning magnetic disk.
Flying head designs have been proposed for use with optical and magneto-optical (MO) storage technology. One motivation for using the magneto-optical technology stems from the availability of higher areal density with magneto-optical storage disks than magnetic storage disks. However, despite the historically higher areal storage density available for magneto-optical disks drives, the conventional magneto-optical disk drive volumetric storage capacity rate of increase has generally not kept pace with the rate of increase of the volumetric storage capacity of magnetic disk drives. One limiting factor in conventional optical reading heads is the low signal to noise ratio exhibited by such heads at high data transfer rates.
Another limiting factor is that optical reading heads require extensive alignment of the optical components and their respective polarizations, rendering the design, manufacturing, and assembly of optical heads significantly more complex and costly.
Other factors that limit writing (or recording) on a magnetic disk at high data transfer rates (or frequencies) using conventional magnetic heads are the increasing requirements for higher magnetic fields and field gradients to achieve smaller and smaller bit size. High magnetic fields are difficult to achieve particularly with narrow tracks and miniaturized heads.
Therefore, there is still a long felt and still unsatisfied need for a read/write head which is structurally significantly less complex than optical reading devices, that requires minimal or no optical alignment, that can write at higher track densities, and that has better control of the data and servo tracks than conventional magnetic heads.